import sys
import pygame

def check_events(ship):
     """响应按键和鼠标事件"""
     for event in pygame.event.get():
         if event.type==pygame.QUIT:
             sys.exit()
         elif event.type==pygame.KEYDOWN:
            if event.key==pygame.K_RIGHT:
                ship.moving_right=True
            elif event.key==pygame.K_LEFT:
                ship.moving_right=True
         elif event.type==pygame.KEYUP:
             if event.key==pygame.K_RIGHT:
                ship.moving_right=False
             elif event.key == pygame.K_LEFT:
                ship.moving_left = False
                #向右移动飞船
                ship.rect.centrex +=1
def update_screen(ai_settings,screen,ship):
    """更新屏幕上的图像，并切换到新屏幕"""
    #每次循环时都重新绘制屏幕
    screen.fill(ai_settings.bg_color)
    ship.blitme()

    #让最近绘制的屏幕可见
    pygame.display.flip()
